Down Syndrome

Question 1

How is Down Syndrome inherited? Name 3 possible mechanisms.

Answer 1

1. Sporadic in 95% cases dt nondisjunction in meiosis
2. Unbalanced translocation between chromosome 21 and another acrocentric chromosome (usually chromosome 14) in 3-4%, 75% de novo, rest familial (balanced parental Robertsonian translocation- papa less risk of passing on)
3. Mosaicism- 1-2%, some normal cells, some affected, more overall mild phenotype

Question 2

How effective is first trimester screening for Down syndrome?
2nd trimister?
Combined?

Answer 2

1. 1st trimester 85%
2. 2nd trimester 80%
3. Combined 95%

Question 3

What is a risk factor for Down syndrome?

Answer 3

Advanced maternal age ( :( My ovaries…)

Question 4

Name 11! Facial/Physical Features of Down Syndrome

Answer 4

1. Small brachycephalic head (broad width head)
2. Epicanthal fold (skin fold of the upper eyelid covering the inner corner of the eye)
3. Flat nasal bridge
4. Upward slanting palpebral fissures
5. Small mouth
6. Large protruding tongue
7. Small ears
8. Increased thickness of nuchal fold (in utero)
9. Single transverse palmar crease
10. Short 5th finger with clinodactyly (bent)
11. Sandal toe deformity
12. Late fontanelle closure

Question 5

Name 1 cognitive feature associated with Down Syndrome

Answer 5

1. Variable, mild to severe developmental delay

Question 6

Name 4 ENT Features of Down Syndrome

Answer 6

1. Serous otitis media (50-70%)
2. Hearing loss (75%)
3. OSA (50-80%)
4. Noisy breathing

Question 7

Name 5 eye features seen in Down Syndrome

Answer 7

1. Brushfield spots
2. Cataracts (15%)
3. Severe refractive errors (50%)
4. Strabismus
5. Glaucoma

Question 8

Name 5 Congenital Heart defects associated with Down Syndrome

Answer 8

1. AVSD
2. VSD
3. Tetralogy of Fallot
4. ASD
5. PDA

Question 9

Name 5 hematologic conditions children with Down Syndrome are at increased risk for

Answer 9

1. Transient myeloproliferative disorder (10%), regress spontaneously in the first 3 mos of life, later risk of leukemia is however 10-30% in these children.
2. Polycythemia
3. Leukemia (1%) both ALL and AML- specific subtype of AML called AMKL (acute megakaryoblastic leukemia)
4. Macrocytosis
5. Iron deficiency anemia w macrocytosis NOT microcytic

Question 10

Name 7 GI conditions children w Down Syndrome are at increased risk for.

Answer 10

1. Intestinal atresia (12%)
2. Anorectal stenosis or atresia
3. Hirschprungs disease
4. Constipation
5. GERD
6. Celiac disease

Question 11

Name 4 neurologic conditions children with Down Syndrome are at increased risk for

Answer 11

1. Hypotonia
2. Infantile spasms
3. Seizures
4. Alzheimer’s after age 40

Question 12

Name 2 MSK conditions DS children are at risk for

Answer 12

1. Congenital hip dislocation

2. Atlanto-axial instability

Question 13

Name 3 endocrine conditions children with DS are at increased risk for

Answer 13

1. Hypothyroidism (both congenital and later onset)
2. DM
3. Obesity

Question 14

How do we diagnose Down Syndrome postnatally?

Answer 14

1. Physical exam is the most sensitive in the first 24h of life
2. FISH- can detect extra copy, but cannot detect translocations
3. Complete chromosome analysis (karyotype)

Question 15

How do we detect Down Syndrome prenatally?

Answer 15

1. Low AFP
2. Low estriol
3. High BHCG
4. Increased nuchal fold thickness
5. Short femur length

Question 16

Name 7 tests babies with DS should have done at birth

Answer 16

1. Chromosomal analysis to confirm dx
2. Echocardiogram
3. CBC
4. TSH
5. Hearing test
6. Eye exam (red reflex)
7. Swallowing assessment IF feeding difficulties

Question 17

Name 5 pieces of anticipatory guidance that should be given to parents of newborns with DS

Answer 17

1. Increased susceptibility to resp infxns
2. Feeding issues, constipation
3. Cervical spine positioning precautions
4. Support in community, resources, early intervention services
5. Review genetics, risk in subsequent pregnancies

Question 18

Name 4 evaluations/tests that should be done for children with DS from 1 mo-1yo

Answer 18

1. Hearing test at 6 mos
2. Optho referral w/in first 6 mos
3. TSH at 6 and 12 months
4. Hemoglobin at 12 mos

Question 19

Name 5 pieces of anticipatory guidance for children w DS that should be discussed btw 1 mo-1yo

Answer 19

1. Risk of otitis media
2. Feeding issues, constipation
3. Symptoms of OSA
4. Review cervical spine positioning precautions
5. Early intervention services-referral

Question 20

What are 3 investigations that are NOT routinely recommended in children with DS

Answer 20

1. Renal US
2. Cervical Xrays
3. DS Growth charts

Question 21

Name 5 tests/investigations that should be done for children w DS btw 1yo-5yo

Answer 21

1. Behavioural audiogram and tympanometry every 6 mos until bilateral ear specific testing possible, then behavioral audiogram annually.
2. Ophthalmology annually
3. Sleep study by 4yo
4. Hemoglobin annually
5. TSH annually

Question 22

Name 4 pieces of anticipatory guidance that should be reviewed for children with DS btw 1yo-5yo

Answer 22

1. Review risk of otitis media
2. Review sx of OSA, myelopathy, hypothyroidism, celiac dz
3. Delayed tooth eruption/hypodentition
4. Risk of obesity-diet/activity counselling

Question 23

Name 4 tests that should be done for children 5+yo w DS

Answer 23

1. Ophthalmology q2yrs, then q3yrs after age 13
2. Behavioral audiogram annually
3. TSH annually
4. Hemoglobin annually

Question 24

Name 6 pieces of anticipatory guidance for children w DS aged 5+

Answer 24

1. Review sx of OSA, myelopathy, hypothyroidism, celiac dz, skin issues
2. Risk of contact sports, trampolines
3. Transition to school-IEP
4. Monitor for behavioral proble,s -ADHD, OCD
5. Puberty, BCP when appropriate
6. Transition to adulthood when appropriate (grp homes etc.)